package com.nuaa.community.entity;

import lombok.Data;

/**
 * ClassName: Page
 * Package: com.nuaa.community.entity
 * Description:
 */
@Data
public class Page {

    // 当前页码
    private int current = 1;
    // 显示上限
    private int limit = 10;
    // 数据总数(用于计算总页数)
    private int rows;
    // 查询路径(用于复用分页链接)
    private String path;

    public void setLimit(int limit) {
        if(limit >= 1 && limit <= 100){
            this.limit = limit;
        }
    }

    public void setRows(int rows) {
        if(rows >= 0){
            this.rows = rows;
        }
    }

    public void setPath(String path) {
        this.path = path;
    }

    /**
     * 获取当前页的起始行
     * @return
     */
    public int getOffset(){
        // current * limit - limit
        return (current - 1) * limit;
    }

    /**
     * 获取总页数
     * @return
     */
    public int getTotal(){
        return rows % limit == 0 ? rows / limit : rows / limit + 1;
    }

    /**
     * 获取起始页码
     * @return
     */
    public int getFrom(){
        int from = current - 2;
        return from < 1 ? 1 : from;
    }

    /**
     * 获取结束页码
     * @return
     */
    public int getTo(){
        int to = current + 2;
        int total = getTotal();
        return to > total ? total : to;
    }
}
